kafka 打開的文件太多

Question

你有沒有遇到過關於 kafka 的類似問題？ 我收到此錯誤： Too many open files 。 我不知道為什么。 以下是一些日志：

[2018-08-27 10:07:26,268] ERROR Error while deleting the clean shutdown file in dir /home/weihu/kafka/kafka/logs (kafka.server.LogD)
java.nio.file.FileSystemException: /home/weihu/kafka/kafka/logs/BC_20180821_1_LOCATION-87/leader-epoch-checkpoint: Too many open fis
        at sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
        at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214)
        at java.nio.file.Files.newByteChannel(Files.java:361)
        at java.nio.file.Files.createFile(Files.java:632)
        at kafka.server.checkpoints.CheckpointFile.<init>(CheckpointFile.scala:45)
        at kafka.server.checkpoints.LeaderEpochCheckpointFile.<init>(LeaderEpochCheckpointFile.scala:62)
        at kafka.log.Log.initializeLeaderEpochCache(Log.scala:278)
        at kafka.log.Log.<init>(Log.scala:211)
        at kafka.log.Log$.apply(Log.scala:1748)
        at kafka.log.LogManager.loadLog(LogManager.scala:265)
        at kafka.log.LogManager.$anonfun$loadLogs$12(LogManager.scala:335)
        at kafka.utils.CoreUtils$$anon$1.run(CoreUtils.scala:62)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
[2018-08-27 10:07:26,268] ERROR Error while deleting the clean shutdown file in dir /home/weihu/kafka/kafka/logs (kafka.server.LogD)
java.nio.file.FileSystemException: /home/weihu/kafka/kafka/logs/BC_20180822_PARSE-136/leader-epoch-checkpoint: Too many open files
        at sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
        at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214)
        at java.nio.file.Files.newByteChannel(Files.java:361)
        at java.nio.file.Files.createFile(Files.java:632)
        at kafka.server.checkpoints.CheckpointFile.<init>(CheckpointFile.scala:45)
        at kafka.server.checkpoints.LeaderEpochCheckpointFile.<init>(LeaderEpochCheckpointFile.scala:62)
        at kafka.log.Log.initializeLeaderEpochCache(Log.scala:278)
        at kafka.log.Log.<init>(Log.scala:211)
        at kafka.log.Log$.apply(Log.scala:1748)
        at kafka.log.LogManager.loadLog(LogManager.scala:265)
        at kafka.log.LogManager.$anonfun$loadLogs$12(LogManager.scala:335)
        at kafka.utils.CoreUtils$$anon$1.run(CoreUtils.scala:62)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
[2018-08-27 10:07:26,269] ERROR Error while deleting the clean shutdown file in dir /home/weihu/kafka/kafka/logs (kafka.server.LogD)
java.nio.file.FileSystemException: /home/weihu/kafka/kafka/logs/BC_20180813_1_STATISTICS-402/leader-epoch-checkpoint: Too many opens
        at sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
        at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
        at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214)
        at java.nio.file.Files.newByteChannel(Files.java:361)
        at java.nio.file.Files.createFile(Files.java:632)
        at kafka.server.checkpoints.CheckpointFile.<init>(CheckpointFile.scala:45)
        at kafka.server.checkpoints.LeaderEpochCheckpointFile.<init>(LeaderEpochCheckpointFile.scala:62)
        at kafka.log.Log.initializeLeaderEpochCache(Log.scala:278)
        at kafka.log.Log.<init>(Log.scala:211)
        at kafka.log.Log$.apply(Log.scala:1748)
        at kafka.log.LogManager.loadLog(LogManager.scala:265)
        at kafka.log.LogManager.$anonfun$loadLogs$12(LogManager.scala:335)
        at kafka.utils.CoreUtils$$anon$1.run(CoreUtils.scala:62)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)

Answer 1

在 Kafka 中，每個主題都（可選）分成許多分區。 對於每個分區，代理維護一些文件（用於索引和實際數據）。

kafka-topics --zookeeper localhost:2181 --describe --topic topic_name

將為您提供主題topic_name的分區數。 每個主題的默認分區數num.partitions在/etc/kafka/server.properties下/etc/kafka/server.properties

如果代理托管許多分區並且特定分區具有許多日志段文件，則打開文件的總數可能非常大。

您可以通過運行查看當前的文件描述符限制

ulimit -n

您還可以使用lsof檢查打開文件的數量：

lsof | wc -l

要解決此問題，您需要更改打開文件描述符的限制：

ulimit -n <noOfFiles>

或者以某種方式減少打開文件的數量（例如，減少每個主題的分區數量）。

Answer 2

在使用 Systemd 的 Linux 發行版（如 RHEL 和 CentOS）上，您需要將第二個塊中的配置行添加到 Systemd 服務文件中。 更改 /etc/security/limits.conf 是不夠的。

[Unit]
Requires=network.target remote-fs.target
After=network.target remote-fs.target

[Service]
Type=simple
User=kafka

LimitAS=infinity
LimitRSS=infinity
LimitCORE=infinity
LimitNOFILE=65536

ExecStart=/home/kafka/kafka/bin/zookeeper-server-start.sh /home/kafka/kafka/config/zookeeper.properties
ExecStop=/home/kafka/kafka/bin/zookeeper-server-stop.sh
Restart=on-abnormal

[Install]
WantedBy=multi-user.target